Veraphlum's Dragon Chain Lightning Swarm

You create a bolt of lightning, in the shape of an azure, translucent dragon, that arcs toward a target of your choice that you can see within range. Three bolts then leap from that target to as many as three other targets, each of which must be within 60 feet of the first target. Five more bolts then leap from each of those targets to other targets within 60 feet of their source.

A target can be a creature or an object and can be targeted by only one of the bolts. A target must make a Dexterity saving throw. The target takes 20d8 lightning damage on a failed save, or half as much damage on a successful one.